PROJECT SUMMARY/ABSTRACT This application is designed to develop an integrated intervention to reduce alcohol and MJ use and consequences and improve sleep among young adults (YA) with comorbid heavy episodic drinking (HED), MJ use, and sleep impairment. HED in YA is an important public health problem, with consequences including accidental injury and death, academic or work problems, unsafe and unwanted sex, and development of alcohol use disorders. Many YA with HED also use MJ, often simultaneously, and experience increased harm as a result. Sleep impairment is common and problematic among YA, identified as the 3rd leading barrier to academic success for students and an important risk factor for mental health problems and suicide in YA. More than 60% of YA report frequent daytime fatigue, 27% extreme distress related to sleep problems, and more than 1 in 4 are at high risk for a sleep disorder. Alcohol use has been linked to impaired sleep in adolescent, YA, college, and older adult populations, with bidirectional causal links between alcohol use and impaired sleep, including negative physiological effects of alcohol on the sleep cycle (e.g., suppression of REM sleep), use of alcohol to promote sleep onset which can both increase alcohol use and resultant sleep impairment, and poor sleep hygiene including delayed and variable sleep-wake timing associated with cyclical patterns of alcohol use during evening and/or weekend social events. Comorbidity of HED and sleep impairment is associated with increased consequences of alcohol use, and exacerbates risk of accidents (including automobile accidents), impaired decision-making, and work and academic difficulties. Similar bidirectional relations exist with MJ use and sleep. Despite risks and consequences, alcohol and MJ prevention programs rarely target sleep directly, and the majority of YA interventions for sleep either focus on sleep hygiene broadly in the absence of specific strategies shown to improve sleep or reduce alcohol or MJ use, or have been relatively intensive interventions with insufficient sample size to truly evaluate impacts on sleep or related comorbid alcohol or MJ use. The current study addresses these gaps through developing and evaluating feasibility and preliminary efficacy of a brief, integrated intervention combining efficacious brief motivational feedback and skills for reducing HED and MJ use and consequences (BASICS) with Brief Behavioral Therapy for Insomnia (SLEEP) shown to improve sleep in other populations. Feasibility and efficacy will be evaluated over a 3-month period, using surveys and daily diaries to assess alcohol, MJ, and sleep at post-intervention and 3- months. Specific aims are: 1) Assess feasibility, acceptability, and preliminary efficacy BASICS + SLEEP in reducing alcohol use and consequences, improving sleep, and weakening daily and lagged (next day) relationships between alcohol and MJ use and sleep impairment; 2 Use diary data to explore daily and lagged relationships between alcohol use, MJ, sleep impairment, and unique YA contextual factor to further inform prevention of comorbid alcohol use, MJ, and sleep impairment.